The present invention relates to a towed steerable vehicle and, more particularly, to a towing assembly for such vehicle.
Towed vehicles which are towed by a towing vehicle, such as a tractor, are widely used in a number of applications, such as for example in the agricultural field in the form of grain carts and the like. These towed vehicles usually include a steering assembly at the front axle or rail of the chassis frame of the vehicle which steers the front wheels when the towing vehicle and the towed vehicle negotiate a turn.
Such steering assemblies typically include a towing assembly having a king pin which is fixed to and extends upwardly through and is fixed through the front axle or rail of the chassis, and a steering frame which is rotatably mounted to the king pin for rotation relative to it. Some prior assemblies have also mounted the king pin well forward of the front axle or rail on support arms. In both such prior through and forward mounted assemblies, a towing tongue may either be formed as part of the steering frame or more usually is movably mounted to the front thereof. The towing tongue has a hitch at its leading end for attachment to a hitch on the towing vehicle. The prior steering assemblies have also typically included conventional tie rods and ball joint mountings on the tie rods which are attached at one end to the steering frame and at the other end to a steering arm on the spindles upon which the steerable wheels are mounted. Thus, when the vehicle is to negotiate a turn, the steering frame rotates to the right or left about the king pin to cause the tie rods to turn the wheels in one direction or the other to steer the vehicle.
The mounting of the king pin through the front axle or rail of the vehicle chassis has the advantage of structural strength and integrity which is important where the vehicle must handle substantial loads and withstand substantial forces during use without damage. This is particularly important in agricultural vehicles which frequently operate under off the road conditions and on uneven terrain. However, such mountings generally result a relatively large turning radius which is particularly disadvantageous, for example, in some agricultural vehicles which must turn sharply at the end of a crop row. The forward mounted assemblies enjoy the advantage of reduced turning radius, but suffer from substantially reduced strength and integrity. All of the prior assemblies, whether through or forward mounted, suffered from contamination from water, dirt and the like of the bearing assembly by which the steering frame is rotatably mounted to the king pin.
In the towing assembly of the present invention the king pin is mounted to the forward face of the chassis front rail, rather than through it or well forward of it as in the prior assemblies. Such frontal mounting has the advantage of a substantial reduction in the turning radius of the vehicle. However, unlike the prior forwardly mounted towing assemblies, in the frontally mounted assembly of the present invention, the level of strength and integrity of the mounting is equal to or greater than that which is otherwise enjoyed by the prior through mounted assemblies, while at the same time the bearing assembly is protected against contamination.
In one principal aspect of the present invention, a towing assembly for towing a steerable vehicle chassis in a forward direction includes an elongate front chassis rail adapted to receive steerable wheels adjacent its ends, and an elongate pin having a flat side is rigidly fixed directly to a front face of the front chassis rail, and the pin has a substantially vertical axis. An elongate steering frame extends at an angle to the front chassis rail. The elongate steering frame includes tie rod mounting means thereon for mounting tie rods thereto which are adapted to extend to the steerable wheels to steer them as the chassis is being towed, and also includes hitching means adjacent the forward end for hitching the elongate steering frame to a towing vehicle. The elongate steering frame is mounted forward of the front rail and for rotation about the pin in a plane substantially perpendicular to the vertical axis of the pin so that rotation of the elongate steering frame about the pin when the chassis was being towed steers the steerable wheels.
In another principal aspect of the present invention, the steering frame extends both forward and to the rear of the front chassis rail, the tie rod mounting means is positioned to the rear of the front chassis rail and the hitching means is positioned forward of the front chassis rail. In still another principal aspect of the present invention, the steering frame is positioned beneath the front chassis rail.
In still another principal aspect of the present invention, a pair of stops are positioned on the front chassis rail and on each side of the steering frame, and the stops extend forwardly of the front chassis rail and simultaneously contact each side of the steering frame to limit the rotation of the steering frame about the pin.
In still another principal aspect of the present invention, the steering frame is rotatably mounted to the pin by a cylindrical sleeve which extends through and is fixed to the steering frame, the sleeve having a top end which opens upwardly of the steering frame and a bottom end which opens downwardly of the steering frame, and a portion of the pin extends into the sleeve. A bearing assembly in the sleeve mounts the sleeve and its steering frame for rotation relative to the portion of the pin which extends into the sleeve. A cap overlies the top of the sleeve to protect the bearing assembly against contamination through the top end of the sleeve.
In still another principal aspect of the present invention, the cap is cup-shaped.
In still another principal aspect of the present invention, the cap is fixed to the pin and/or the front chassis rail.
In still another principal aspect of the present invention, the aforementioned hitching means includes a substantially horizontal sleeve adjacent the forward end of the steering frame, and a pin through the sleeve for hitching the end of a towing tongue to the horizontal sleeve to permit the towing tongue to rotate in a vertical direction relative to the horizontal sleeve and the steering frame.
These and other objects, features and advantages of the present invention will be more clearly understood through a consideration of the following detailed description.